Pressure-fluid motor



April 28, 1931. E. G. GARTlN PRESSURE FLUID MOTOR Filed June 4, 1927 Patented Apr. 28:, 1-931 EQMER e. G'UBTnI, or anemia roam, NEVI HAMPSHIRE, AS-SIGNGE 'ro SULLIVAN MA;

ran-r Fries GHINEEY AxCORPOR-ATION OF MASMCHUSETTS ;i sssmserwwS moa eppliea tionf led June 1927} Serial N0. 1S6, 4 31.

This invention relates to pressure fiuidmof tors and more particularly to pressure fiuid motors of the'hammer type.

an object of this invention is to providean improved pressure fiuid motor. Another object is to provide animproved pressure motor ofthe piston-controlled valve type hav ing improved and simplified fluid distribu tion means. Another object of this invention is to provide an improved pressure fluid motor having. improvedfluid distribution means wherein. the fiuid'distribution valve is thrown by compression. A further object'is to provide an improved pressurefiuid motor having improved and simplified fluid distribution means wherebythe power and efliciency of the motor is materially increased. These and other objects and advantages of this invention will, however, hereinafter more fully appear.

. In the accompanying drawing there is shown for purposes of illustration one form and modification thereof which the invention mayassumein practice.

In this drawing; I *Fig- 1 is a central longitudinally extending sectional'view illustrating the improved pressure fluid motor. p v Fi 2 is a view similar to Fig. l-illustrating the motorpiston and distribution valve'in difi erentpositions. V f .3 is a detail sectional View illustrating a portion of the improved fluid distribution means. I

Fig. 1 isan enlarged elevation'al view of the distribution valve.

5 is a view similar to Fig. 2 illustrat ing amodified formof constructionl i In the illustrativeconstruction shown in Figs. 1 to e the invention is shown embodied in apressure fluid motor of the hammer type comprising a cylinder 1 havinga bore'2 in whichis reciprocably mounted a hammer piston 3. :lhe piston 3 "has formed integral therewith a forwardly projecting "extension or striking bar 4. As shown, suitably secured within a bore 5 formed within the forward end of the cylinder lis a bu'fi'er ring 6 hav ng a central opening 7 within which the striking bar l is adaptedit o enter. The'rear end of the 1cylinderjbore2 is closed by ia'combined head block and valve chest 8'houjsed'witliiii a bore 9 formed within a rear head member 10. Interposed between the member 10 and the head block 8 is a rearplate 11. Thelbuifer ng cy Li ed bl c s, ea the ii and rear head member 10 are held inns-- einbfl' a io in) an lsu'itbl melt sn eet "m nner.- .1

The improved flu d distribution, means comprises alined'bores 12 and 13 of difierent diameters having their axes alined witli' the} longitudinal. axis of the motor cylinder. shown, the rear plate'll has formed thereon a forwardly projectingcylindrical boss 14 whichfits the bore 12 and this plate is pro} 1 vided; with a central opening 15 extending therethrough and communicating with a chamber 16. formed within the rear head member 10. The forward endofthe bore 1 3 communicateswithj the rear end of the cylinderbore 2thro ighfa central opening 17;

In accordance with the illustrative embodiment of the invention shown in Figs. 1 to 4 an automaticifluid distribution valve 18,herein preferably of the two-spool difiterential type, is reciprocably mounted in theva'lve chamber and is provided with an enlarged spool 19 vfittingthe bore 12 and a reduced front end spool 20 fitting the bore 13, the sp0ols19and 20 being connected by an intermediate' reduced portion 21'. .The valve .18 is made hollow substantiallythroughout its length as at 22 for the purpose of materially reducingithe weight thereof. 'Ihevalve 18 is also provided with'a cylindricalprojection 23 formed on the rearward end thereof and this projection fits the opening 15 in the rear plate 11; The valve 18 is also provided with a cylindrical portion 24 formed thereonat the forward end ofithe enlarged spoiolhli) and this portion is adapted to fit thebore 13; and is oit' thesame diameterras the end spool 20. Pressure fluid'is adapted to be supplied to the motor through a supply passage 25 which communicates with apassage 26 under thepcontrol of a'usual manually operable throttle valve 26; The passage 26 communicates" with the 'cham'ber16. which is herein a constant pressure chamber. The pressure in the chamber 16 acts continuously on the rear pressure area of the cylindrical projection 23 of the distribution valve. Pressure fluid flows from the chamber 16 through an opening 27 formed in the rear plate 11 (see Fig. 3) and through a longitudinal passage .28 formed in the head block 8 into an annular recess 29 formed within the valve chest adjacent the forward end of the bore 13. Also communicating with the bore 13 intermediate the front spool 20 and the cylindrical portion 24 is a laterally extending passage 30 which communicates through a passage 31 with a longitudinally extending supply passage 32 formed in the motor cylinder and this passage communicates by a lateral port 33 with theforward end of the cylinder bore 2. Ex-' tending laterally directly through the side.

wall of the cylinder intermediate the ends thereof are parallel piston controlled exhaust 7 ports 34 and 35 through which the exhaust I 18 has formed therein. a radial leak port extending through the spool 20 and connecting the annular recess 29 with the interior of the valve, pressure fluid being adapted to leak continuously through, this port for a purpose to be hereinafter described.

V. .In the modified construction shown in Fig.

5 an automatic fluid distribution valve 41 .is

employed having reduced cylindrical end portions 42 and 43 respectively slidably mounted in the bore 15 in the plate 11 and in I a bore 44 formedin the head block 8. This valve is also provided with enlarged end spools 45 and 46 connected by a reduced intermediate portion 47, these spools fitting a bore 48 similar to the bore 13 heretofore described. Communicating with the bore 48 are the passages 30,38 and 39 and the. annular recess 29, these passages and recess being the same as those of the preferred form. Connecting the forward end of the bore 48 with I the rear end of the cylinder bore 2 is a longitudinal passage 49 located laterally of the bore 44, this passage taking the place of the central passage 17 described above. The bore 44 at the forward end of the valve is vented to atmosphere through a small leak port 50.

In the operation of the improved pressure fluid motor shown in Figs. 1 to 4 it will be assumed that the hammer piston 3 is in the position shown in Fig. 2 and is about to be pressure fluid within the forward end of the cylinder bore is exhausted through ports 34,

'35 and through port- 33, passage 32, passage 31, port 30, through the-bore 13 and thence through the exhaust port 39 directly to atmosphere; Resultantly, the pressure fluid Within the rear end of the cylinder bore acts on the pressure area on the piston and the latter is driven forwardly to effect its working stroke. Asthehammer piston 3 moves forwardly the port 36 is uncovered and pres.

sure fluid. is admitted from the rear end of the cylinder bore through-port 36 and the passages Y37 and 38 to the bore 12 in the valve chest,.the fluid acting on the rear surface of the enlarged spool 19, which, together with the constant pressure acting on the cylindricalprojection 23, causes the valve 18 to be thrown forwardly from the position shown in Fig. 2 to the position shown in Fig. 1. As soon as the valve moves to this position the rear end of the cylinder is open .to exhaust by way of-passages 37 and 38, bore 12 and passage 39, but the piston has moved a considerable distance before a substantial quantity of fluid escapes in thismanner due to the time required to actuate the valve and because ofthe restricted character of the passages. WVhen the valve is intheposition shown in Fig. 1 the supply of pressure fluid from the recess 29 flowing through the central passage 17 iscut off bythe end spool 20. However, the hammer piston 3 continues its forward movementdue to the expansive action of the pressure fluid and momentum until it reaches the extreme end of its working stroke. As the hammer piston overruns the orts 34 and 35 the pressure remaining within the rear end of the cylinder bore is exhausted directly to atmosphere. After the valve is thrown to the position shown in Fig. 1 the pressure acting on the rear surface of the enlarged spool 19 is vented directly to atmosphere through the passage 39 and the valve is held in'the position shown only'by the constant pressure acting Y on the cylindrical projection 23 on the valve. At the same time pressure fluid flows from the chamber 16 through passage 28, annular recess 29, through the bore -13-past the rearward surface of the spool 20-through lateral port 30, passage 31, passage 32 and lateralport 33 to the forward end of thecylinder bore and the pressure fluid acting on the forward pressure area of the piston drives the latter rearward ly. As the hammer piston 3 moves rearwardly, the ports 35 and 34 are uncovered and the forward end of the cylinder bore is Labeled opgnedlo exhaust ndas the piston continues is inthe position shown in Fig. 5 pressure fluid flows from the chamber 16 through passage 28 to the annular-recess 29 and thence through passage 49 to the rear end of. the cylinder bore and'as a result the hammer piston 3 is driven forwardly to eflect its working stroke. The forwardend of the cylinder bore is-opened to exhaust through thepiston controlled ports 34' and 35 and also through.

pa'ssages32, 31', and 30, through the bore 48, between the spools 45, 46 on the valve, and past-the forward surface of the spoolt5 and through passage 39 to atmosphere. 'As the hammer piston moves forwardly the port 36 is uncovered and fluidfiows through port 36 and passages 37 and 38 to the bore 48 atthe rear-side of the spool 45, the pressure acting on this spool together with a constant pressure in the chamber 16 acting ontheprojection 42, throwing the valve 41 forwardly thereby closing the. exhaust-passage 39"and cutting off fluid flow from; the recess 29 through the passage 49 to the 're'ar'end of the cylinder bore. At the same time thepassage is connected with the recess -29 and fluid then fiows through this recess past the rear surface on the spool 46, through thebore 48, through passages 30, 31 and 32 and thr'ough port 33to the forward-end of the cylinder bore. The pressure-within the rear end of a the cylinder bore is exhausted through ports 34 and and also through ports 36, passages 37'and 38, through the bore 48 past therear surface on the spool45andthrough passage 39-to atmosphere. The hammer piston is then driven rearwardly by the fluid'flowing through 'port'33. As the piston moves rear} wardly ports 34, 35 and 36 are closed and the pressure fluid trapped within the rear end of the cylinder is compressed, and as the forward end of the bore 48 is always in communication with the rear end of the cylinder bore, the pressure acting on the forward surface of the spool 4-6 is builtup'andthe-valve is thrown rearwardly against the opposing pressure acting: on the projection 42. The above cycle of operation is repeatedthrough outthe normal operation of the motor.

While I have in this application specifical- 1y described one form and a modification thereof. which the invention may assume in practice, it will be'understo'od that this-form and modification of the same areshown for purposes of illustration and that the invention may be modified andembodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is: a

1. A pressure fiuid 1 motor comprising a cylinder, a piston reciprocable therein, and

- fluid distribution means for effecting recip'ro? cation of said piston comprising a reciprocabledifierentialvalve having anend area in constant communicationwith the rear end of the cylinder whereby the valve may be thrown in the rearward direction by compres. sion' pressure built up in the rear" end of the cylinder on the return stroke and means for throwing the valve in the opposite direction on the forward stroke of the piston before the rear end of the cylinder'is' opened to exhaust, sald valve being hollow and havinga closed reduced rear end subjected to constant pres sure for holding the valve in said latter position. i I i 2. A pressurefluid motor comprising a cyl inder, "apiston reciprocable therein, and-fluid distribution means for eifecting reciprocation of said piston including'a reciprocable differential valve arrangedcoarially with and at 2 the rear end of said cylinder, a direct axial passage for placing-a forwardly facing surface of said valve in constant communication 7 with the rear end of said cylinder whereby the valve may be thrownlin the-rearward directionby compression pressure, and means for throwing the valve in the opposite direction on'theforward stroke of the pistonbe-- fore the rear end of the cylinder is openedto exhaust, said valve being hollow and havinga closed end subjected to constant pressure for holding thevalve in said opposite position.

3. A pressure fluid motorc'omprising a cylinder, a piston reciprocable therein, and fluid distribution means for efiecting reciprocation of said piston including a reciprocable'valve arranged coaxially with and at the rearend V of said cylinder, a direct axial passage'for placing aforwardly facing surface-of said valve inf constant communication {with the rear end of said cylinder whereby the'valve' maybe thrown rearw'ardly by compression pressure -in the rear end of said cylinder, means providing a restricted leakpassage be" tween the'rear end of thecylinder andthe supply when the valve is in its'forwa'rd-position, and means for throwing thevalve in the opposite direction-on the forward stroke of the piston before the rear end of the cylinder is opened to exhaust comprising a rearwardlyf Y facing area subjected to constantpressure,a second rearwardly facing area and a p ston controlled passage for subjecting said second area to intermittent pressure. e

4. A pressure fluid motor comprising acylinder, a piston reciprocable therein, and fluid ing surface on said valve in constant communication with the rear end of the cylinder whereby the valve may be thrown rearwardly by compression pressure in the rear end of the cylinder, and means for throwing the valve in the opposite direction on the forward stroke of the piston including a larger spool on said valve and a piston controlled passage for admitting throwing pressure to c said spool before the rear end of the cylinder is opened to exhaust, said valve being hollow and having a reduced closed rear end subj ected to constant pressure. 7

5. A pressure fluid motor comprising a cylinder, a piston reciprocable therein, and fluid distribution means for effecting reciprocation of said piston comprising a valve chest in axial alinement with said cylinder, a reciprocable differential valve in said valve chest, a direct axial passage for placing a forwardly facing surface of said valve in constant communication with the rear end of said cylinder whereby the valve may be thrown rearwardly by compression pressure, said valve having an end spool controlling admission of live fluid to both ends of said cylinder, a smaller guiding portion at the rear end of said valve, subjected'to constant pressure, anenlarged spool disposed intermediate the ends of said-valve and which controls exhaust means for both ends of the cylinder and a piston controlled passage openingon the forward stroke of the piston before the rear end of the cylinder is opened, to exhaust for conducting pressure fluid to the rear surface of said large spool for throwing the valve 1n the forward direction.

6. A pressure fluld motor comprising a cylinder, a piston reciprocable therein, and

fluid distribution means for effecting recip rocation of said piston'comprising a valve chest, areciprocable valve therein having a single spool arranged in cooperation with passagesin said chest to control admission to both ends of the cylinder, and a closed end formed to constitute a reduced portion which is at all times maintained within a correspondingly reduced bore in said chest,

valve to one position, and means for subject ing said reduced'end to constant live pressure to assist in throwing the valve and holding the same in said position. I

7. A pressure flu1d motor comprlsing a cylinder, a piston reciprocable therein, and fluid distribution means for effecting reciprocation of said piston comprising a reciprocable hollow valve arranged in the rear end of the cylinder and having a single spool controlling admission to both ends of said cylinder, a reduced closed opposite end disposed at all times within a reduced bore, and an enlarged spool intermediate the end of said valve, a piston controlled passage for subjecting said large spool to pressure for throwing the valve to one position, and means for subjecting said reduced end to constant live pressure to assistin throwing the valve and holding the same in said position, said valve having means for controlling exhaust from the front end of for subjecting said intermediate spool to pressure for throwing the valve forwardly, and means for subjecting the reduced rear end to constant live pressure.

9. A pressure fluid motor comprising a cylinder, a piston reciprocable therein, and fluid distribution means for effecting reciprocation of said pistonjcomprising a reciprocable valve arranged coaxially with the cylinder and having a forward end spool arranged to control admission to both ends of the cylinder, an enlarged "spool. intermediate the ends of the valve, and a closed reduced rear end disposed at all times within a reduced bore whereby pressure fluid is prevented from flowing past said closed end, a piston controlled passage for subjecting said intermediate spool to pressure for throwing the valve forwardly, means for subjecting the reduced rear end to constant live pressure, and means providing a restricted leak passage for placing the rear end of the cylinder in communication with the supply when the valve is in its forward position. 7 Y

10. A pressure fluid motor comprising a cylinder, a piston reciprocable therein, and fluid distribution means foreflecting reciprocation of said piston comprising a valve chest,

. an exhaust passage leading therefrom, a valve reciprocable in said valve chest having an end spool controlling admission to both ends of the cylinder, an annular groove formed in said valve'adjacent said spool'for alternately connecting the front end of the cylinder to supply and to said exhaust passage, an enlarged spool controlling exhaust from both ends of said cylinder, and'a piston controlled passage for subjecting said enlarged spool to fluid pressure for throwing the valve in one direction.

11. A pressure fluid motor comprising a I cylinder, a piston reciprocable therein, and

fluid distribution means for effecting reciprocation of said piston comprising a valve chest, an exhaust passage leading therefrom, a reciprocable valve in said valve chest having a single spool controlling admission to both ends of said cylinder, an annular groove adjacent said spool and alternately connecting the front end of the cylinder to supply and to said exhaust passage, a second spool having an intermediate shoulder adjacent said groove to control exhaust for the front end, and an enlarged port-ion arranged to control communication between the rear end of the cylin der and said exhaust passage, and a piston controlled passage for subjecting said en.- larged portion of the spool to fluid pressure for throwing the valve in one direction.

12. A pressure fluid motor comprising a cylinder, a piston reciprocable therein, and fluid distribution means for effecting reciprocation of said piston comprising a valve chest, an exhaust passage leading therefrom, a valve reciprocable in said valve chest having a spool controlling admission to both ends of the cylinder, said spool having an area in constant communication with the rear end of the cylinder, an annular'groove formed in said valve adjacent said spool for alternately connecting the front end of the cylinder to supply and to said exhaust passage, a second spool controlling exhaust from both ends of said cylinder, means of larger area than said first mentioned area adapted to be subjected to pressure for throwing the valve in onedirection including an area on said second spool, and a piston controlled passage for subjecting said area to pressure in the cylinder.

In testimony whereof I atfix my signature.

ELMER G. GARTIN. 

